1. Field of Invention
The present invention relates to a light emitting device power supply circuit, a light emitting device control circuit and an identifiable light emitting device circuit therefor, and an identification method thereof; particularly, it relates to such light emitting device power supply circuit, light emitting device control circuit and identifiable light emitting device circuit with an identification function, and an identification method thereof.
2. Description of Related Art
FIG. 1 shows a schematic diagram of a prior art light emitting diode (LED) power supply circuit 100. As shown in FIG. 1, the LED power supply circuit 100 supplies electrical power to an LED circuit 10. The LED power supply circuit 100 includes a control circuit 110, a power stage circuit 120, and a feedback circuit 130. The control circuit 110 is connected to the feedback circuit 130 to receive a feedback signal FB. The control circuit 110 generates an operation signal GATE according to the feedback signal FB, to operate a power switch of the power stage circuit 120 accordingly such that an input voltage Vin is converted to an output voltage Vout, and an output current Iout is provided to the LED circuit 10. The power stage circuit 120 may be a synchronous or asynchronous buck, boost, inverting, buck-boost, or inverting-boost power stage circuit as shown in FIGS. 2A-2J.
A hot swapping protection function is required for the prior art. “Hot swapping” means to remove an old LED circuit 10 from the circuitry and install a new LED circuit 10 while the power is still ON. In this prior art, when the old LED circuit 10 is removed, the feedback circuit 130 cannot obtain correct information to generate a correct feedback signal FB, and therefore the output voltage Vout is uncontrolled which may cause danger. Besides, whether the new LED circuit 10 can comply with the power supply specification of the LED power supply circuit 100 is unknown and it should preferably be confirmed, so as to maintain the stability of the LED power supply circuit 100 while it operates. The aforementioned prior art can not comply with the aforementioned requirements.
In view of above, the present invention proposes a light emitting device power supply circuit, a light emitting device control circuit and an identifiable light emitting device circuit therefor, and an identification method thereof which provide the hot-swapping protection function and optimize of the cooperation between the light emitting device power supply circuit and the identifiable light emitting device circuit.